Automatic railway-signal



(No Model.)

. 2 Shefs-Sfieet 1. G. D. GREENWOOD & J. G. JORY. AUTOMATIC RAILWAY SIGNAL.

No. 417,022. Patented Dec. 10, 1889.

ATTORNEY.

(No Model.) V 2 Sheets-Sheet 2:.

G. D. GREENWOOD & J. G. JURY.

AUTOMATIC RAILWAY SIGNAL.

Patented Dec. 10, 1889.

wiTNEssEs:

INVENTORS' ATTORNEY.

N4 PETERS. Phelmllilhogmphnr, Washington. D. c.

UNITED, STATES PATENT OFFICE.

GEORGE D. GREENlVOOD AND JOHN G. JORY, OF iAlflllillORE, MARYLAND.

AUTOMATIC RAILWAY-SIGNAL.

SPECIFICATION forming part of Letters Patent No. 417,022, dated December 10, 1889.

Application filed May 1, 1889- Serial No. 309,229. (No mocleLl T0 66 whom it may concern:

WOOD and JOHN G. JORY, citizens of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Automatic Railway-Signals, of which the following is a specification.

This invention has reference to a blocksignal system for railways; and it consists in the combination, with semaphores or signal devices, of certain instrumentalities hereinafter described, whereby the signals are changed or adjusted by the action of compressed air, which is brought into play by a locomotive or train of cars moving along the track.

The invention is illustrated by-the accompanying drawings.

Figure 1 is a side view of an ordinary signal-post or semaphore. Figs. 2 and 3 are side elevations of the signal devices, and the parts shown in both figures together constitute one block. Fig. 4 is a plan view of the track and certain parts of the signal apparatus. Fig. 5 is a side view showing the power-cylinder and connections and a section of the pump. Fig. 6 is a plan of two power-cylinders on 0pposite sides of the track and connections. Figs. 7 and 8 show details of the power-cylinders and connected parts. Fig. 9 shows the relative position of two wheel-treadles. Fig. 10 is a section of the opera-ting-cylinder.

The letter A designates the track; B B, the signal-posts, each having at the top a pivoted signal-arm c, at the bottom a lever (Z, and a rod 6, connecting said arm and lever. Two of these posts constitute a block for each track of a double-track road. For a single-track road four posts are necessary for each block two on each side of the roadway.

In the present instance the system is shown as fora single-track road. In the case of a single-track road two wheel-treadles C are usedone close alongside of each rail and directly opposite each other. These treadles are pivoted at one end f, and the other end.

I pivoted end f of one is opposite the free end Be 1t known that we, GEORGE D. GREEN- of the other, as shown. From the pivoted end to the highest point 9 at the center each treadle has a gradual continuous slope g, but from the free end toward the center is first a low horizontal part h and then an ab rupt slope h to the high center g. From this construction of treadle and reversed position of the two treadles it will be seen that one treadle will be depressed before the other by a locomotive or train, depending on the direction of movement. A train approaching the two treadles will strike and depress first that one whose gradual continuous slope g is toward the approaching train. The connections with the other treadle thereupon will instantly be disengaged or broken. I

The free end of each wheel-treadle has pivoted to it aswitch-arm t', which makes c011- nection with the piston-rod i of a power-cylinder D. The switch-arm i may be moved to disengage or break connection with the rod t". The power-cylinder D has a piston and a springj under it of power barely sufficient to keep it normally elevated. lVhen a car-wheel comes on the wheel-treadle C while the switcharm t is in connection with the piston-rod i, the piston will be depressed and the air in the first power-cylinder D will be forced through the pipe It to the rear end of the first signaloperating cylinder E, which has a piston l, and rods Z d connect with the lever d on the bottom of the signalpost. The movement of the piston Z will cause the signal-arm c to be moved.

The compressed air to supply the cylinders D E may come from any source or storage that may be provided. In the present instance we provide an air-pump F, to be worked by a wheel-treadle G alongside of the track-rail. The air-pump (see Fig. has an inlet-tube m in its head, a valve m through its piston, and a spring 77. below the piston to quickly raise it. A pipe 71: leads from the air-pump to the first power-cylinder D and has a check-valve n. v

The power-cylinder D has a blow-off or safety valve 0 to release the air if too much is forced in by the pump. A three-way valve p is in the pipe to control and cut off the supply of air passing from the power-cylin- Z and thereby raisethe signal-arm c on post B. The air-pipe 75 continues past the lirst signal-operating cylinder E to second signaloperating cylinder E, located near the other post B. This second cylinder has reversed position with respect to the first cylinder that is, the forward ends of thetwo cylinders are toward each other. The pipe 75 between the two cylinders E E has two automatic valves 7', one of which is shown in section at Fig. 10. Each of these valves is located at the connection with the pipe 7&2 of the branch pipe 3, leading therefrom to the forward end of the operating-cylinder.

\Vhen a train is moving in the direction of the arrow and air is being forced by the first power-cylinder D, the flap of the automatic valve r at the first operating-cylinder E will swing up and close the branch pipe 8 and open the main pipe, and the air will pass on to the valve 7' of the second ope'rating-cylin der E, the flap of which will swing down and close the main pipe and open the branch pipe, whereby the air will enter the rear end o'f the first cylinder E and the front end of the second cylinder E, and thus the signal-arm c on the two posts B B will be raised, showing that the block is occupied. The air-pipe k continues from the second operating-cylinder E to the second power-cylinder D. After the train has passed post B and air is being forced by the second power-cylinder D the action of the fiap-valves, as above described, is exactly reversed, and the result is that the si nalarms 0 in the posts B I3 will both be lowered, showing that the block is open or unoccupied.

The air devices and the mechanism on one side of the road for operating the signals on one track have been described, and it now remains to be stated that this being a singletrack road a duplicate set of these devices and mechanisms is provided along the other side of the road, and that means are also provided for connecting the two sets, whereby when a train passes along the track only one set of signals will be operatedto wit, that set Which is on the right-hand side of the roadway considered in the direction that the train may be moving. It will be understood that the other set, which is on the opposite side of the roadway, will be thrown out of connection or rendered inoperative for the time being.

As already stated, each wheel-treadle O has a pendent switch-arm 2,which normally hangs down and rests upon the piston-rod t" of a power-cylinder. Each power-cylinder has on its top end an an gle-lever, (designated on one cylinder by the letter a and on another by u'.) The horizontal arm of each anglc-levcr is connected with the piston-rod t" in such manner as to be moved up and down thereby. Attached to the pendent arm of each anglelcver is a rod, which in one instance is designated t and in the other 1". This rod leads from the angle-lever on the power-cylinder at one side of the track and connects with the pendent switch-arm 1', which is above and coacts with the piston-rod i of the power-cylinder at the other side of. the track.

As shown in Figs. 5 and 8, the power-cylin: der D on one side of the track is diagonally and not directly opposite the power-cylinder D on the other side of the track, and the switch-arm t' of the treadle on one side of the track is disengaged from its piston-rod by a rod t, leading diagonally to an angle-lever it on the powercyli-nder on the other side of the track, and another rod t and angle-lever a in like manner operate the other switcharm. It will be seen these rods, angle-levers, and switch-arms constitute the means for conn'ecting the two sets and rendering one of them inoperative. V

The signal-operating cylinders E E have two exhaust-ports r-one at each end-and a slide-valve opens and closes the ports. A rod wconnectsthe slide-valve with a lever cawhich is moved by the piston-rod Z. By reference to Fig. 10 it will be seen that when compressed air enters one end of the operating-cylinder E and moves the piston Z therein such movement will, through the action of lever 50 and rod 10, shift the slidevalve w so as to close the exhaust-port at the end of the cylinder where air has just entered and to open the exhaust-port at the opposite end to allow the air therein to escape. This mechanism has been described herein as working by the action of compressed air. It is obvious, however, that other fluids may be employed to operate it -for instance, oil or water.

Ilaving described our invention, we claim- 1. In a block-signal system for railways, the combination of the signal-posts B 13, each provided with movable signals, two powercylinders D D, two signal-operating cylinders E E, a pipe connecting the two power.- cylinders and having branches leading to two ends of each of the said opcrating-cylinders, an automatic valve 2' at the connection of the main pipe with each branch pipe, which leads to the forward end of each of the operating-cylinders, and a wheeltreadle C, to force the air from each power-cylinder.

2. In railroad-signals, the combination of a post having a movable signal, an operatingcylinder E, provided with a piston, connections between the said piston and movable signal, an air-pipe having open connection with one end of the operating-cylinder and a branch 8, leading to the other end, and an automatic flap-valve r at the connection of said branch with the air-pipe.

3. In a railroad-signal, the combination,

with a movable signal, of two power-cylinders D D, having pistons, a signal-operating cylinder E, having a piston, a pipe connecting the two power-cylinders andbranches into both ends of the opcrating-cylinder, an automatic valve '7- at the connection of the main pipe with the branch leading into one end of the operating-cylinder, a three-way valve 19 in the main pipe near one power-cylinder,

and a gear-connection between said threeway valve and the rod of the piston in the power-cylinder.

at. In a railroad-signal, the combination of a power-cylinder D, a piston insaid cylinder, a spring to elevate the piston, a wheel-treadle pivoted alongside of the track-rail, and a switch-arm 'i, pendent from the wheel-treadle and adapted to make and break connection with the rod of said piston. I

5. In a railroad-sign al, the combination of a post having a movable signal, an operatingcylinder E, provided with a piston and having an exhaust-port at each end, connections between the said piston and movable signal, an air-pipe having open cominnnicationwith one end of the operating-cylinder and a branch s leading to the other end, an automatic flap-valve 0' at the connection of said branch with the air-pipe, and a slide-valve 20, which is operated by the movement of the piston for opening and closing the exhaustport. I

6. In a block-signal system for a singletrack railway, the combination of signal-posts, signal-operating cylinders, and power-cylinders on both sides of the roadway, two pivoted wheel-treadles 0, one at each side and directly opposite each other, but placed in reversed position with respect to each other, a switch-arm 1', pendent from each wheel-treadle and, movable to and from a piston-rod of one of the power-cylinders, and connections between the switch-arm on one side of the road and a lever operatedby the power-piston rod on the other side of the road, and vice versa, for making and breaking connection between the switch-arms and piston-rods.

In testimony whereof we affix our signatures in the presence of two witnesses.

' GEORGE D. GREENWOOD.

JOHN G. J ORY. Witnesses:

.TNo, T. MADDOX, JOHN E. MORRIS. 

